Dishwashing machine

ABSTRACT

A loading station, a washing station and an unloading station for dishes are arranged generally in line with a basin under each station. Stationary racks composed of parallel rods at each station can support dishes, and dishes can be moved from the loading station to the washing station and from the washing station to the unloading station by two movable racks having parallel rods interdigitated with the stationary parallel rods which can be translated lengthwise of such rods. The movable racks are movable elevationally to lift dishes from the stationary rack at one station to be transported to the stationary rack at an adjacent station. Latches can connect the two movable racks for conjoint translation. At the washing station sprays oscillating about axes extending transversely of the direction of translation of the racks wash the dishes. During such washing operation roll curtains at opposite ends of a housing over the washing station are lowered to confine the sprays.

United States Patent [72] Inventor Kenneth F. A. Wright Westminster, California [21] Appl. No. 801,737 [22} Filed Feb. 24, 1969 Continuation-impart of Ser. No. 553,862, May 31, 1966, abandoned [45] Patented Sept. 29, 1970 [73] Assignee Exceltronic Industries Ltd.,

Vancouver, British Columbia, Canada, a corporation of British Columbia [54] DlSI-lWASHlNG MACHINE 4 Claims, 30 Drawing Figs.

[52] US. Cl 134/58, 134/83, 134/143, 134/181, 134/200, 198/219 [51] Int. Cl 1308b 3/02 [50] Field ol'Search 134/58D, 60, 72,78, 83,96,l03,129131,133,143,155, 165, 172,180181,199200;198/2l9 [5 6] References Cited UNITED STATES PATENTS 3,221,870 12/1965 Pagay 198/219 1,037,073 8/1912 Sonnemann 134/200 2,016,115 10/1935 Messlor 134/200X 2,229,663 l/194l Meeker et al 134/78 l zq Primary Examiner-Robert L. Bleutge Atlorney- Robert W. Beach ABSTRACT: A loading station, a washing station and an unloading station for dishes are arranged generally in line with a basin under each station. Stationary racks composed of parallel rods at each station can support dishes, and dishes can be moved from the loading station to the washing station and from the washing station to the unloading station by two movable racks having parallel rods interdigitated with the stationary parallel rods which can be translated lengthwise of such rods. The movable racks are movable elevationally to lift dishes from the stationary rack atone station to be transported to the stationary rack at an adjacent station. Latches can connect the two movable racks for conjoint translation. At the washing station sprays oscillating about axes extending transversely of the direction of translation of the racks wash the dishes. During such washing operation roll curtains at opposite ends of a housing over the washing station are lowered to confine the sprays.

3,530,864 Patented Sept. 29, 1970 Sheet 2 of 11 nfraeA 'y I Patented Sept. 29, 1970 Sheet Q of 11 INVENTOE K/V/VET/l FA. Me/5147* nrroem y Patented Sept. 29, 1970 3,530,364

heet 4 of 11 7 2 How RELAY k INVENTOR :4 (EMA/UH FA. nae/6m 95,25 BY wrrv/v A Z Patented Sept. 29, 1970 Sheet UNLOAD/NG r w 24 M W W m M 9 w N W 5 m A N .w w w A 4 E m. a

Patented Sept. 29, 1970 3,530,864

Sheet 6 of 11 Patented Sept. 29, 1970 3,530,864

Sheet '7 of 11 7 M 0% H 8 re M 0, MW 2 3 VA m M v R\ g M W mm U Patented Sept. 29, 1970 Patented Sept. 29, 1970 ,4 rraas/E/ Patented Sept. 29, 1970 Sheet 10 of 11 BIDIRECT'L I LEFT sun OPTIONS INSE RT RE TRACT MODE RIGHT END OPTIONS INSERT RETRACT v I 0 l L BIDiRECTL omv Z0 BIDHZECTL ONLY DETERGENT AND DRAIN PUMPS POWER MANUAL HEATER ON OFF /0/ MAN.@ AUT0.

7 AUTOMATIC all}? Lme' HEATER comms gflfl'g H. c. 6% H c. II 244 [0A. 15 A (A. 235 I k@ ll fi m I h i 2 I [90 /9/ Wyn/7a? DISHWASHING MACHINE This patent application is a continuation-in-part of my application Ser. No. 553,862, filed May 31, I966, for Dishwashing Machine," now abandoned.

This invention relates to a machine for washing and sterilizing dishes and is especially suitable for washing drinking glasses, cups and the like.

It has been a problem to provide in a dishwashing machine the combination of means for automatically conveying dirty dishes from a loading station to a washing station and subsequently transporting such washed dishes to an unloading station while providing adequate water spray to be impinged on the bottom of the dishes and, more particularly, the inside of overturned cups and glasses for adequate cleaning. It is a principal object of the invention, therefore, to provide a small compact automatically-controlled washing and sterilizing machine for commercial use in which dirty dishes are moved automatically from a loading station to a washing station, sup ported in such washing station by a support through which adequate water and sterilizing solution can be sprayed to impinge on the undersides of the dishes, and, subsequently, the clean dishes are automatically transported from the washing station to an unloading station.

It is a further object to provide a single set of top and bottom sprays at the washing station which can consecutively supply different washing, sterilizing and rinsing solutions. An additional object is to provide time-controlled means for automatically oscillating the sprays so that all portions of the dishes in the machine can be impinged by the full force of the spray. By providing such oscillating or rocking spray means it has been found that the surfaces of the dishes are subjected to a very effective scrubbing action which is not effected by stationary or revolving spray arrangements.

Another object of this invention is to provide an automatically time-controlled drain outlet arrangement whereby sterilizing solution can be returned to a reservoir for reuse while the waste water from wash and rinse cycles can be diverted to a main drainage outlet.

A further object is to provide a fully enclosed spray housing which includes doors opened and closed in synchronism with movement of the dish-transporting means.

The foregoing objects can be accomplished by providing a dishwashing machine including in series a loading station, a dishwashing station and an unloading station, each of such stations being of substantially the same size. A stationary rack extending along the length of all three stations overlies a sink having separate basins for each station. Two movable racks, each of an extent corresponding to the size of one of the stations, can be raised to lift dishes from the stationary rack, moved lengthwise of the machine to transport dishes from one station to another and then lowered to deposit the dishes again on the stationary rack at a different location. Thus, the movable racks can simultaneously move clean dishes from the washing station to the unloading station and dirty dishes from the loading station to the washing station.

Spray means are provided above and below the portion of the stationary rack at the washing station and dishes carried thereby. Entrance and exit doors to the washing station are in the form of curtains rolledon shafts driven in synchronism with rack-moving means. Water-supply means, a reservoir for temperature-controlled sterilizing solution and the spray means are interconnected through suitable valve means so that wash water, sterilizing solution and rinse water can be consecutively supplied automatically through the spray means to the washing station. The spray means include pairs of parallel tubes which are movable to oscillate the sprays to scour residue from the dishes. Drainage from the washing station is controlled automatically by a valve for diverting waste liquid to a drain and returning sterilizing solution to the reservoir for reuse.

FIG. I is a front elevation of one form of the dishwashing machine of the present invention and FIG. 2 is a top plan thereof.

FIG. 3 is a top perspective of a portion of the machine housing and FIG. 4 is a section taken on line 4-4 of FIG. 3.

FIGS. 5 and 6 are top perspectives of additional portions of the machine housing.

FIG. 7 is a top perspective showing a spray assembly, parts being broken away.

FIG. 8 is a longitudinal vertical section through the dishwashing machine taken on line 88 of FIG. 2.

FIG. 9 is a top perspective ofa curtain and FIG. 10 is a top perspective of a curtain housing with parts broken away.

FIG. 11 is a transverse section through the dishwashing machine taken on line ll1l of FIG. 1.

FIG. 12 is a block circuit diagram.

FIG. 13 is a section through a control valve.

FIG. 14 is a top perspective of the stationary rack; FIG. 15 is a top perspective of the movable rack assembly; and FIG. I6 is a top perspective of the stationary and movable racks in assembled condition, parts being broken away.

FIG. 17 is a top perspective of rack-moving mechanism.

FIG. 18 is a detail elevation of rack-latching mechanism, and FIG. 19 is a similar view with parts in different relationship.

FIG. 20 is a top perspective of a modified type of dishwashing machine.

FIG. 21 is a diagram of the piping of such modified machine shown principally in top perspective.

FIG. 22 is a longitudinal section through the central portion of the modified dishwasher and FIG. 23 is a transverse section through such central portion taken on line 2323 of FIG. 22.

FIG. 24 is a horizontal section through the modified dishwashing machine taken on line 24-24 of FIG. 25 and having parts broken away.

FIGS. 25, 26 and 27 are fragmentary longitudinal vertical sections through the modified dishwasing machine taken on lines 25-25, 26-26 and 27-27, respectively, of FIG. 24, illus' trating the dish-transporting mechanism.

FIG. 28 is a side elevation ofa portion of the modified dishwashing machine showing control members.

FIG. 29 is a top perspective of a compact version of the dishwashing machine and FIG. 30 is a fragmentary longitudinal section through such compact version.

The housing 1 shown in FIG. I is a rectangular frame, preferably of formed sheet metal, molded plastic or other similar material. Mounted in the housing is a sink 2 shown in FIGS. 8 and 11 having a basin 3 underlying the loading station, a basin 4 underlying the washing station and a basin 5 underlying the unloading station. An upright partition 6 and a bottom 7 are bonded to a wall of the housing 1 and form therewith a reservoir or storage tank 8 for sterilizing solution. A housing extending upward above the washing station sink basin 4 is formed by walls 9, curtains 41 and top plate 54 to enclose the washing station. The housing 1, sink 2 and reservoir 8 may be made of sheet plastic, sheet metal or other sheet material which is corrosion-resistant, smooth and resistant to cracking or chipping. All angles or corners of the housing, sink and reservoir are rounded to facilitate cleaning to maintain the machine in a sanitary condition.

The spray assembly shown in FIG. 7 includes a lower portion which would extend below dishes in the washing station and an upper portion extending above such dishes. Each of the upper and lower portions of the spray assembly include two pairs of parallel tubes 28 having perforations or nozzles 28' along their lengths arranged to direct spray onto the dishes. The lengths of such tubes extend transversely of the direction of movement of the dishes from the loading station to the washing station to the unloading station. Near the supply end of each pair of tubes 28 a T is provided having a cross tube 29 interconnecting the tubes of the pair for supplying water or sterilizing solution from the center leg 30 of the toe connected by a swivel fitting (not shown) to a manifold 38 shown in FIG. 8. Plugs 31 provide a tight seal in the ends of the spray tubes 28 and are removable for cleaning the interiors of the tubes. The opposite ends of each pair of tubes 28 are spaced apart by spreaders 33.

A rod 34 having one end secured to a spreader 33 and its opposite end rotatively received in a bracket 35 mounted on a wall 9 of the washing station housing supports the ends of a pair of tubes 28 remote from the supply end of such tubes. The ends of links 32 are attached to threaded plugs 31 of the inner spray tube 28 of each pair. Such links are connected to a crank 36 secured on the shaft of an electric motor 37 mounted externally on wall 9, as shown in FIGS. 8 and 11. When this motor is energized the crank reciprocates the links 32 to rock the four sets of spray tubes 28 about the axis of tubes 30 and rods 34. The parallel arrangement of the tubes combined with the rocking motion of such tubes varies the direction of the sprays to effectively scour grease and other residue from the dishes.

As shown in FIG. 8, the upper and lower manifolds 38 and 38" are connected by pipe 38' to control valve 21 for conveying the hot and cold water and to pipe 81 for supplying cleansing or sterilizing solution from the reservoir 8 to the spray assembly described above. A check valve 40 is provided between the connection of pipe 81 and the connection of valve 21 to pipe 38' to prevent the return of rinse water from control valve 21 to reservoir 8.

A conventional pump 11 mounted on partition 6 of the reservoir and connected to outlet pipe 7' supplies solution from the bottom of the reservoir 8 to the pump. An electric temperature-controlling immersion heater 12 is mounted on the inner side of partition 6 to control the temperature of sterilizing solution in the reservoir. An overflow outlet 13 having a check valve 14 is connected to a drainpipe 15. A float valve 16 is connected to and supported from a shutoff valve 17 connected by a pipe 18 to the hot water supply pipe 19. A check valve 20 is installed in the hot water supply line 19 between the connection with pipe 18 and a three-port control valve 21. A cold water supply line 22 includes a check valve 23 and is connected to the control valve 21. Basket strainers 24 are provided for the outlets of basins 3 and and such outlets are connected through a pipeline 25 to the drainpipe 15. The outlet from the center basin 4 underlying the washing station is connected to a pump 26 to provide rapid discharge of rinse water or chemical sterilizing solution through a threeport control valve 27. This valve allows chemical solution to be returned to reservoir 8 while waste water from the washing and rinsing cycles is directed to the main drain 15.

A roll-up curtain 41, such as shown in FIG. 9, is mounted at each side of the washing station housing to close the openings to such housing during the washing and sterilizing cycles. As shown in FIG. 10, channel guides 42 on the vertical edges of walls 9 extend downward from recess for receiving curtains 41 for closing opposite sides of the washing station. The ends 10' of such recess have holes 43 to receive the opposite ends ofa central shaft 44 on which the curtain is rolled; The curtain can extend downward from its roll through a slot 10" in the bottom of the recess 10 in registry with the channel guides. A weight shown in the form of a brass strip 45 is affixed to the lower edge of the curtain to stretch the curtain downward when the curtain is unrolled.

It is preferred that the curtains be made of laminated polyethylene film or similar material and fiber glass ribs 46 may be inserted between layers of the film to provide rigidity. The shaft of one curtain carries a sprocket 47 and the other curtain shaft carries a gear 49, as shown in FIG. 8. A gear 48 meshes with gear 49 and is mounted on a shaft journaled on wall 9. Sprocket 47 and gear 48 are rotated in the same direction by chain 51 driven by sprocket 50. Thus, when the shaft 44 attached to a sprocket 47 rotates in one direction gear 49 and its shaft rotate in the opposite direction. Chain 51 may be kept taut by a tightener 52.

Upper edges of the two recesses 10 are formed as angles 53 to support opposite edges of a splash cover 54, preferably made of safety glass. A cover 55 shown in FIGS. 1, 2,6 and 11 encloses the washing station and is removable for access to the components of this station. I

The rack system 56 shown in FIG. 2 includes a stationary rack having frame sides 59 which rest on the opposite edges of sink 2 so that such rack is easily removable for cleaning of the dishwashing machine. Supports 58, shown in FIG. 14, bridge between sides 59 and are spaced to divide the rack into three substantially equal sections corresponding to the three machine stations. Stationary parallel wires or rods 57 extend lengthwise of the machine between the supports 58 and are spaced apart sufficiently to permit adequate water from the lower spray tubes to impinge on dishes supported on the rack. Transport means for the dishes includes a movable rack assembly composed of two separable rack sections 60 and 61. Section 60 is formed of wires 60' supported by transverse connecting bars 60" and section 61 is formed of wires 61' supported by transverse connecting bars 61". Such wires extend lengthwise of the machine and are spaced so that, when the movable and stationary racks are assembled, as shown in FIG. 16, the wires or rods of the movable rack will be interdigitated with the wires or rods 57 of the stationary rack. Each rack may be coated with plastic material to prevent breakage or chipping of glass, chinaware and the like which may be placed upon the rack.

A reversible motor 63 rotates shaft 64, indicated diagrammatically in FIG. 17. A friction disk clutch 65 is carried by shaft 64 and is connected by link 76 and arm 76' to shaft 77. Movement oflink 76 by rotation of the clutch swings the arm to rotate shaft 77 for swinging one of the parallel links 66 on each side of the machine which are interconnected by bars 62. Such links are mounted by pivots on frame sides 59 of the stationary rack and movably support the bars 62 which form tracks for the movable racks. When such track bars are raised by links 66 of the rack-raising means the wires 60' and 61' of the movable rack, interdigitated with wires 57 of the stationary rack, are raised above such wires 57. Simultaneously movement of the clutch drives rack 67 which drives gear 68 carried on shaft 69 to rotate sprocket 50 for operating chain 51,shown in FIG. 8,to open curtains 41.

Advancing means for effecting lengthwise movement of the movable rack includes a cord 71 looped around a roller carried on and driven by shaft 64. The cord passes around pulleys 72 and its ends are fastened to opposite ends of spring tightener 73. One cord end extends through the spring and forms a loop 74 which is connected to a hook 74', shown in FIG. 18. carried by bar 61" of movable rack section 61 to effect reciprocation of such rack section by reciprocation of cord 71 effected by alternately opposite rotation of roller 70. Clutch 65 moves through one-half of a revolution to effect opening and closing of curtains 41 and raising and lowering of reciprocable racks 60, 61. During lengthwise movement of such rack sections the clutch slips after it has turned through such half revolution.

When the machine is deenergized and the components are at rest the wires of movable rack section 60 at the loading end of the machine are in their lowered position below the wires 57 of the stationary rack portion corresponding to the loading station at the right of FIG. 14. Also the wires of movable rack section 61 are positioned below the wires 57 of the stationary rack portion corresponding to the unloading station at the left of that figure. Curtains 41 are in their downwardly-extended positions closing the openings at each side of the washing station. Control valve 27 is adjusted so that the drain from basin 4 is in communication with the drainage system 15.

Glasses, cups and the like to be washed are placed inverted on the stationary rack at the loading station and the starter switch is manually energized. The thermostatically-controlled heater 12 is thereby energized to control the temperature in the cleaning solution reservoir 8 automatically. Motor 63, shown in FIG. 17, rotates shaft 64 and roller 70 in a clockwise direction to move rack 61 to the right to engage with and become latched to rack 60, clutch 65 being ineffective to drive rack 67 and linkage 76 at that time. Motor 63 then reverses and engages clutch 65. Such clutch then drives rack 67 from right to left to effect rotation of pinion 68 and sprocket 50 in a counterclockwise direction to raise curtains 41. Simultaneously, the clutch moves link 76 to activate parallel links 66 to raise racks 60 and 61. The wires 60' and 61' of racks 60 and 61 are thereby raised upward between and above wires 57 of the stationary rack, lifting dishes from the stationary rack at the loading station. During such clutch operation loop 74 is reversely positioned to drive the raised racks 60 and 61 by cord 71 to the left until rack 61 reaches the unloading station and rack 60 reaches the washing station, at which time the latch connection between the two movable sections is disengaged.

FIGS. 18 and 19 show the latching and latch-releasing mechanism for racks 60 and 61. In FIG. 18 the racks 60 and 61 are in raised position. Latch 92 is mounted on support bar 60" of rack 60 by pivot 93. A hook 94 formed in the lower edge of the latch is shown in engagement with pin 95 on support bar 61" of rack 61. As such support bar 61" engages the support bar 58 of the stationary rack between the washing and unloading station, the lower edge of the latch which is inclined downwardly and rearwardly toward hook 94 rides up on a pin 96 on support bar 58.

When the motor 63 is again reversed clutch 65 is engaged to rotate clockwise for lowering racks 60 and 61. By such movement pivot 93 of latch 92 and pin 95 are lowered, as shown in FIG. 19, while pin 96 holds the swinging end of the latch up so that racks 60 and 61 are disengaged, the motor 63 stops, and rack section 60 is returned to its starting position by weight 91 shown in FIG. 16. As the wires of the movable racks are lowered to positions below the wires of the stationary rack, soiled glasses are deposited on the stationary rack in the washing station. Since the movable rack sections are at opposite ends of the machine, only the stationary rack underlies the glasses in the washing station and sprays from tubes 28 can impinge on the glasses with a minimum ofinterference.

Such clockwise rotation of clutch 65, effected by reversing motor 63, also moves rack 67 from left to right to lower curtains 41 for enclosing the washing station and motor 37 is energized to effect rocking action of the spray assemblies. The washing cycle is then commenced by energization of a solenoid to control mixing valve 21 through which temperaturecontrolled wash water passes to headers 38 and 38" and through spray tubes 28. The rinse water runs off through the outlet of basin 4 and through pump 26 to control valve 27 which is set to discharge the liquid to the main drain 15.

On completion of the washing cycle, control valve 21 closes and pump 11 starts to pump chemical sterlizing solution from reservoir 8 through supply pipe 81 to headers 38 and 38" and through spray tubes 28. The drain and control valve 27, shown in FIG. 8, now discharges the chemical solution to reservoir 8 through pipe 82. A final rinse then commences in the same manner as previously described for the washing cycle. The

solenoidcontrolled mixing valve 21 and drain valve 27 are automatically reset to provide rinse water of the desired temperature which is discharged from the washing station basin 4 to the drain 15. When this rinse cycle is completed, the machine is automatically deenergized and the clean glasses are stored inside the washing station with the curtains in closed position.

When the machine is reenergized to wash another load of dishes or glasses, rack 61 is again moved to the right and engaged with and latched to rack 60. The motor 63 resumes its clockwise rotation and, as the racks are conjointly moved to the left in raised positions, rack 61 will transport clean glasses from the washing station to the unloading station at the same time that rack transports soiled glasses from the loading station to the washing station.

The wiring diagram of FIG. 12 schematically illustrates the sequential operation of the dishwashing machine, the parts being shown in off" position. A main switch 97 turns on the machine and energizes heater 12 for heating solution in reservoir 8. When dishes or glasses have been loaded on the stationary rack at the loading station, push button 98 is pressed to actuate holding relay 99 and begin the machine cycle. The reversible motor 63 is operated by a double-throw switch 100 actuated by movable rack section 61. When this switch is in the position shown at 100, rack section 61 is moved to the right until it engages with and is latched to rack section 60 and closes the switch portion 100" to reverse motor 63. The rack sections 60 and 61 are thus raised and moved in tandem to the left and, when the rack section 61 reaches the unloading station, it throws switch 100 again to reverse the motor. The rack sections are lowered thereby and rack section 61 moves a switch 101 from the full-line position to the broken-line position to deenergize motor 63 and energize timer 102.

The timer is shown diagrammatically to indicate the cycles of the washing operation. When switch 101 is in the brokenline position, contact arm 103, having contacts 104 corresponding to arcuate contact strips 105a and 105b, is rotated in a clockwise direction. During the washing cycle, valve 21 is in a position to permit water from the hot and cold water pipes 19 and 22, shown in FIG. 8, to be supplied to manifolds 38 and 38" and valve 27 is in communication with drainpipe 15. Contacts 104 of timer arm 103 engages arcuate contact strips 105a and 105k for connecting them to maintain energization of holding relay 99 and to energize motor 37 for oscillating spraytubes 28.

During the pause between the sterilizing and rinsing operations motor 106 and pump 11 are deenergized, but valve 27 remains in communication with the pipe 82 to permit any solution remaining in basin 4 to be returned to the reservoir. At this time arm 103 engages arcuate contact strip 1050 to close valve 21.

Engagement of a contact on arm 103 with arcuate contact strip 105d begins the sterilizing cycle by actuating motor 106 to drive pump 11 for pumping solution from reservoir 8 to manifolds 38 and 38". Engagement of another contact 104 of such arm with arcuate contact strip 105e energizes the solenoid of valve 27 to reset it for communication with pipe 82. At the beginning of the rinse cycle valves 21 and 27 are again deenergized to return to the positions of the washing cycle. At the end of the rinse cycle, contacts 104 of arm 103 are disengaged from arcuate contact strips 105a and 10512 to deenergize the holding relay 99 and spray pipe oscillating motor 37, respectively, thereby shutting off the machine until push button 98 is again pressed to initiate another cycle of operation,

To facilitate cleaning and maintenance of the equipment, various components of the machine can be quickly and easily disassembled. Apron 75, shown best in FIGS. 1, 3 and 4, can be removed to provide access to the automatic controls, switches and wiring. Door 78 at the left of housing 1 provides access to reservoir 8 for routine cleaning and servicing. The central panel 79 is removable to provide access to plumbing and electrical connections. Cover plate 80 shown in FIGS. 2

and 5 covers the rack assembly mechanism and is easily removed, and cover 55 can be lifted off to provide access to the components of the washing station. Both the stationary rack having rods 57 and the movable racks 60 and 61 can be removed by lifting frame 59 out of the machine to provide access to sink 2 and facilitate cleaning.

If it is desirable to permit basin 4 to be drained by gravity flow of liquid from it the three-port control valve shown in FIG. 13 may be used. The valve body 83 is triangular in cross section. The inlet 84 in the top of the body is connected to the drain from basin 4, outlet 85 to the drainpipe 15 and outlet 86 to return pipe 82 to reservoir 8. A pivot shaft 87 passes through the lower front face of the valve body and an angle rod 88 extends radially from such shaft into a ball 89 which may be of rubber or plastic material. The ball 89 can be swung to close selectively port 85 or 86. A solenoid or electric motor (not shown) is connected to the pivot shaft 87 to turn it for moving the ball valve 89 to close the proper port in accordance with the washing cycle previously described.

The modified type of dishwashing machine shown in FIGS. 20 to 28 inclusive has a housing 1 of the same general comformation as the housing of the dishwashing machine shown in FIGS. 1 to 19. This housing houses three basins 3, 4 and 5, shown in FIG. 21, which are arranged in series like the arrangement of the basins in the dishwashing machine described above. The dish loading station is located above basin 3, the dishwashing station is above basin 4 and the unloading station is above basin 5. The dishwashing station is enclosed by the cabinet cover 155 having a central stiffening band depression 155' extending across its top and down one side. The ends of such cabinet cover have openings in them to afford movement of dishes from the loading station to the washing station and from the washing station to the unloading station. Such openings are closable by roll-up curtains 41 movable in channel guides 42 as discussed above in connection with the first form of dishwashing machine.

The spray assembly and piping diagram connected with it are shown in FIG. 21. in this instance the lengths of the upper and lower spray tubes 128 again extend transversely of the direction of movement of the dishes through the machine. Again these spray pipes are mounted in pairs and arranged to oscillate about axes extending transversely of the direction of movement of dishes through the machine as effected by movement of dish-supporting racks. The corresponding ends of the spray tubes 128 of each pair are connected by cross tubes 129, in turn connected to a center tube 130. The opposite corresponding ends of the tubes of each pair are connected by spreaders 133, the centers of which are mounted respectively on rods 134.

Liquid is supplied to the upper spray tubes 128 through a manifold 138' connecting their center tubes 130 and liquid is supplied to the lower spray tubes 128" through the lower manifold 138" connecting their center tubes 130. The upper and lower manifolds are connected by a section of the main supply pipe 138. This pipe has in it a shutoff valve 141 between the lower header and the cross connection 139 connecting pipe 138 to supply pipes 81 and 181. A further supply pipe 143 is connected to pipe 138 from a source of disinfectant or sterilizing chemical 144. A drain valve 142 is located between the chemical supply pipe 143 and a drain. This valve can be manually operated or remotely operated.

To wash the dishes detergent can be supplied from a reservoir or a storage tank 8 through an outlet pipe 7' to a pump 11 from which detergent liquid can be pumped through the pipe 81 and past check valve 40 to the cross connection 139 in the main supply pipe 138 for the sprays. To rinse the dishes in the washing station, a solution of suitable disinfectant or sterilizing chemical can be supplied from the reservoir or storage tank 108 through the outlet pipe 107 to the pump 111. Such pump will pump that liquid through pipe 181 and past check valve 140 to the cross connection 139.

lt will be evident that the system described will tend to maintain the detergent liquid and the disinfectant chemical solution separate. Because of the check valve 140 detergent solution cannot be pumped from pipe 81 into pipe 181 and because of check valve 40 disinfecting chemical cannot be pumped from pipe 181 through the cross connection 139 into pipe 81. Moreover, neither detergent solution from pipe 81 nor disinfectant chemical solution from pipe 181 can be forced into pipe 143 through which additional chemical solution can be supplied because of the positive three-port valve 21 in the water lines and the injector valve 145 in the outlet from the chemical storage bottle 144.

Hot water can be supplied from a hot water source 19 past a control valve 20 through the pipe 18 and the pipe 18 to the reservoir 8. The level of the detergent solution in that reservoir can be regulated automatically by the float valve 16. Hot water can also be supplied from the same source through pipes 18 and 118 to the chemical solution reservoir 108. The level of solution in this reservoir is controlled by the float valve 116. An emergency overflow pipe 113 connected to drain may be provided for the detergent solution reservoir 8 and an emergency overflow pipe 114 can be provided for the disinfecting chemical solution tank 108.

Detergent solution can be collected from the central basin 4 and returned to the reservoir 8 for reuse by flow through the drain pipe 125 to the pump 26. This pump will withdraw liquid quickly from the washing station sink. If the diverter valve 27 is actuated by a solenoid 127 to connect the pump with pipe 82, the detergent liquid will be returned to reservoir 8. Any excess detergent liquid will escape from the reservoir 8 through overflow pipe 113. On the other hand, if disinfecting chemical solution is discharged from the spray pipes 128 the solenoid 127 can be actuated to connect the pump 26 to the disinfectant chemical solution return pipe 182 connected to the reservoir 108. Excess chemical solution can flow from such reservoir through overflow pipe 114. Alternatively, a three-way valve 25' in pipe 182' can be turned to divert the return flow of chemical solution to the drain 25.

To wash and rinse a batch of dishes in the washing station of the dishwashing machine over the sink 4, the pump 11 can first be energized to force detergent solution past check valve 40 into pipe 138 and out through the oscillating spray tubes 128. The detergent liquid which did not adhere to the dishes would be returned through pipe 125, pump 26, valve 27 and detergent-return pipe 82 to the reservoir 8. Thereafter, the pump 11 would be stopped and the pump 111 energized to pump disinfecting liquid solution from the reservoir 108 through outlet pipe 107' and pipe 18] past check valve 140 to pipe 138 for discharge through the spray tubes 128.

The disinfectant chemical solution which did not adhere to the dishes would be returned through pipe 125, pump 26 and return-detergent solution pipe 182 to the detergent chemical solution reservoir 108. Any liquid which adhered to the dishes or which spilled over into sinks 3 and 5 would be drained from those sinks through the drain lines 25. The dishes could be rinsed with pure water of any desired temperature, if desired, by mixing the water from the hot water supply pipe 19 and the cold water supply pipe 22 as it passed through the three-port valve 21. Such water would pass from the supply sources through control valves 20 and 23. The water thus supplied would flow through connecting pipe 143 to the cross connection 139. Measured amounts of disinfecting chemical can be injected into such rinse water through valve 145.

During the washing and rinsing operation, the openings in opposite ends of the washing station housing section 155 would be closed by the roll-up curtains 141 being in the lowered positions shown in FIG. 22. Such curtains are moved upward and downward by rotation of their storage rolls. The curtains are held in their lowered positions by the weight of brass strips 45 in their lower edges. The rollers of these curtains are mounted on rods 44 journaled in the upper portion of the housing section as shown in FIG. 22. The roller rods of the two curtains are connected by chain and gearing mechanism so that both curtains will be raised at the same time and both curtains will be lowered at the same time.

The movement of the curtains is effected by a pneumatic jack including an air cylinder and a piston rod 150 movable in such cylinder. One end of the air cylinder is anchored by pivot 250 to the housing and the end of the piston rod 150 farther from the cylinder is connected by pivot 251 to an actuating arm 152 at a location spaced from pivot 252 by which it is swingably mounted on the dishwasher housing 1. The swinging end of such arm is connected by pivot 151 to a fitting on the endless chain loop 151 encircling guide sprockets 47 and 47. The pivot pin 151' is received in a slot 152 extending lengthwise of the actuator arm 152 so that pivot 151' can move lengthwise of such arm while it is being swung about its mounting pivot 252 between the broken-line position and the solid-line position shown in FIG. 22 by action of the pneumatic jack 150, 150'.

The gear 47 at one end of the loop of chain 151 is keyed to the rod 44 of the roll-up curtain at one end of the housing 155. The other chain sprocket 47' is located adjacent to the other roll-up curtain and such sprocket is secured to gear 48 coaxial with such sprocket. That gear meshes with gear 49 which is keyed to shaft 44 of the roll-up curtain. As the jack 150, 150' is operated to swing actuating arm 152 between the solid-line position and the broken-line position shown in FIG. 22, the chain 151 will be moved in one direction or the other. As such chain is moved the sprockets '47 and 47' will be turned in the same direction, as indicated, for example, by the arrows. Because of the interposition of gears 48 and 49 between sprocket 47' and the adjacent roll-up curtain rod 44, the two rods of the curtain rollers will be rotated in opposite directions so that both curtains will be raised and both curtains will be lowered simultaneously.

The mechanism for oscillating the pairs of spray tubes 128 about the center tubes 130 and the rods 134 is shown in FIGS. 22 and 23 as including the oscillating vane motor 136. Oscillation of the vane of such motor swings arm 137 which is connected by links 132 and 131 to bell cranks mounted on corresponding upper and lower center tubes 130 or having a pivot axis concentric with such tubes. Such bell cranks are connected to one pair of the upper spray tubes and one pair of the lower spray tubes to oscillate them directly by reciprocation of links 132 and 131. Such bell cranks are connected by an upper link I32 and a lower link 131, respectively, to arms secured to the other upper and lower pairs of spray tubes to oscillate them conjointly with the pairs of spray tubes to which the bell cranks are connected directly.

The mechanism provided in the modified type of dishwashing machine for transporting dishes to be washed from the loading station to the washing station and for transporting washed dishes from the washing station to the unloading station is shown best in FIGS. 24, 25, 26 and 27. At each of these stations is a stationary rack composed of parallel wires or rods 57 supported with their lengths extending lengthwise of the path of travel of dishes between the loading station, the washing station and the unloading station by cross-rod supports 58. Dishes are moved from the loading station to the washing station by a loading rack formed by parallel wires or rods 61' carried by movable supporting transverse rods or bars 61". Dishes are transported from the washing station to the unloading station by a movable unloading rack having parallel wires or rods 61' carried by supporting transverse rods or bars 61".

As seen best in FIG. 24 the stationary wires or rods 57 in the loading, washing and unloading sections of the dishwashing machine are arranged in alignment and the wires or rods are all spaced apart the same distance. In addition, the wires or rods 60' of the loading rack are spaced apart the same distance and the same distance apart as the wires or rods 57 of the stationary racks. Correspondingly, the wires or rods 61' of the unloading rack are all spaced apart the same distance and the same distance as the wires or rods of the stationary racks. The wires or rods of the loading rack and of the unloading rack also are disposed parallel to the wires or rods 57 of the stationary racks and are located between them in interdigitated fashion as shown in FIGS. 16 and 24.

As also described in connection with FIGS. 14, and 16, the cross members 60" and 61" of the movable racks are slidably supported on bars 62 extending lengthwise of the machine. These bars are supported on parallel links 66 which are mounted on pivots 166 journaled in gears projecting downwardly from the frame side plates 59. Swinging of the links 66 about their pivots 166 will raise and lower bars 62 for supporting the movable racks in corresponding positions with their wires raised above or lowered below the stationary rack wires 57. Elevational movement of the two bars on opposite sides of the machine is synchronized by a cross shaft 166' shown in FIG. 24 which connects the pivots of one pair of corresponding links 66.

In the modified dishwashing machine shown in FIGS. to 28, inclusive, the bars 62 supporting the movable racks are raised and lowered by raising means including a pneumatic jack and the racks themselves are slid positively and independently along such supporting bars by advancing means including pneumatic jacks. In FIGS. 25, 26 and 27 a pneumatic jack including an air cylinder 163 is shown as having one end anchored to the rack frame by a pivot 164. The piston rod 163' of such cylinder is connected by pivot 164' to a lever arm 176 secured to one of the links 66 carrying a rack-supporting bar 62. When the jack I63, 163' is in its contracted condition shown in FIG. 25, the rack-supporting bar 62 is in its lowered position. Extension of the jack tothe position shown in FIGS. 26 and 27 swings parallel links 66about their pivots 166 to raise the rack-supporting bars 62 into the positions shown in FIGS. 26 and 27. Such movement of the rack-supporting bars shifts the movable rack wires or rods 60' and 61' from positions below the stationary rack wires or rods 57 as shown in FIG. 25 into positions raised above such stationary wires or rods as shown in FIGS. 26 and 27.

The loading rack 60 and the unloading rack 61 can be moved independently of each other by pneumatic jacks shown in FIGS. 24, 26 and 27. One of such jacks, shown in FIGS. 24 and 27, includes air cylinder having one end anchored to the rack frame by a pivot 165. The piston rod 170' of such jack is connected to the cross member 60" of the loading rack nearer the unloading station. One end of the air cylinder 171 of the other pneumatic jack, shown in FIGS. 24 and 26, is anchored to the rack frame by a pivot 167. The piston rod 171 of this jack is connected to the cross member 61" of the unloading rack nearer the loading station.

When the jack 170, 170' is in its extended condition as shown in FIG. 24, the loading rack will be in registry with the loading station. Contraction of this jack to the position of FIG. 27 will move the loading rack from the loading station to the washing station. Extension of the jack will move the loading rack from the washing station back to the loading station. When the jack 171, 171' is in contracted condition, as shown in FIG. 24, the unloading rack is in the unloading station. Extension of this jack to the position of FIG. 26 will move the unloading rack from the unloading station to the washing station. The loading rack and the unloading rack can be shifted from one extreme position to the other whether the bars 62 supporting the movable racks are in their raised position or in their lowered position. Because the pivots 166 of the parallel links 66 and the pivots I64, 165 and 167 for mounting the pneumatic jacks are all carried by the rack frame, such frame and all of the racks can be lifted and slid lengthwise out of the washing station as a unit.

In order to coordinate the operation of the various components of the modified dishwashing machine, a suitable electric control circuit is provided along the lines shown in FIG. 12 which can be either manually or automatically controlled. FIG. 28 shows a control panel for such a circuit which can be mounted on a door 191 of the housing I. This circuit includes a master on-off" power switch 97 and a switch 101 which can be moved to select either manual or automatic operation of the dishwashing machine. When the switch 10] is on manual" and the heater switch 12' is on manual, the piping system can be drained. When the diswashing machine is to be operated for washing dishes, both of these switches should be on automatic."

Normally the racks 60 and 6] move to convey the dishes from an end stationto the center washing station and then from the center washing station to the other end station. If the knob 200 is turned with its pointer at the center, the racks will be operated to move the dishes through the machine from left to right. If the pointer of knob 200 is turned toward the right to unidirectional, the dishes will be moved by the racks through the machine from right to left.

In some instances it may be desirable to move the dishes from one end station to the central washing station and back to the same end station. For such operation, the knob 200 is turned toward the left so that the pointer is in registry with bidirectional.

If, with the pointer of the knob 200 set at bidirectional" and the switches 201 and 201' ofleft end options" turned to LT the left button 98 is pressed, the left rack will move upward and inward to move dishes from the left station to the washing station; and then the rack lowers and moves back to the left station. After the washing cycle is completed the rack will move into the washing station again. rise and move out to the left station, bringing the dishes with it. If it is desired simply to move the rack in raised position from the washing station to the left station. the two switches 20l and 201' are swung to R" and the left button 98 is pressed.

Alternatively, if it is desired to move the dishes from the right end into the washing station, the two switches 203 and 203' would be swung to L and the right button 98 pushed, so that the right rack would rise and move from the right station into the washing station to load dishes, lower and move out again. After the washing operation is completed, the rack would move from the right station into the washing station, rise and move back out to the right station to remove the dishes. If it should be desired to have the rack at the right end of the machine simply move in elevated position from the washing station out to the right station, the two switches 203 and 203 would be swung to R and the right button 98 pressed.

Whenever the movable rack guide bars 62 are raised, the roll-up curtains 41 are also raised to uncover the openings to the washing station.

The simplified version of the dishwashing machine is shown in FIGS. 29 and as having a floor model housing 1'. Alternatively, however, this type of dishwashing machine could be constructed as a countertop model in which the basins would be set in the top ofa counter. It would be most convenient to mount such a dishwashing machine over a double sink combination so that the washing station enclosure 155, 155' would overlie one basin and the rack system 56 would be movable to overlie the other basin, both to receive unwashed dishes and to accommodate washed dishes.

In this machine the covering over the washing station includes side walls 109, an end wall 141 and a roll-up curtain 41 for closing an access opening in the end of the enclosure opposite end wall 141. The mechanism utilized in this machine is generally similar to that embodied in the two types of machines described above, but is simplified in certain respects. The spray-washing mechanism including spray tubes 128, spreaders I33 and rods 134 is like that described in connection with FIGS. 21 and 22. The drive mechanism for raising and lowering roll-up curtain 41 can be like that shown in FIGS. 22 and 23 and described in connection with those figures, except that it is not necessary to include the gears 48 and 49 which are required only for driving a second roll-up curtain.

In the simplified type of dishwashing machine shown in FIGS. 29 and 30 it is not necessary for the rack system 56 to include both stationary racks and movable racks. For this type of machine only a single movable rack including parallel wires or rods 160 connected and supported by transverse members 161 is required. These transverse members are slidably mounted on rails I62 forming opposite sides of the rack frame. To shift such rack a pneumatic jack interconnecting the movable rack and the rack frame is provided. Such jack includes an air cylinder 270 having one end anchored to the rack frame by a pivot 265. The piston rod 270' of such jack is connected to the cross member I61 of the movable rack located farther from the jack pivot 265.

In use, dirty dishes are loaded onto the wires or rods 160 of the rack when it is in the position shown in solid lines in FIG, 30. The pneumatic jack 270,270 is then extended to shift the loaded rack in the direction indicated by the arrow in FIG. 30 into the broken-line position within the washing compartment while the curtain 41 is in raised position. The curtain will then be lowered and the dishes will be washed by projection of sprays from the spray tubes I28 as described above. The curtain 41 will then be raised and jack 270,270 will be retracted to shift the movable rack and its load of washed dishes from the left, broken-line position of FIG. 30 to the right, solid-line position. The washed dishes can then be removed from the rack and a new load ofdirty dishes can be placed on the rack.

I claim:

1. A dishwashing machine comprising a loading station, a washing station and an unloading station arranged generally in a line, stationary dish-support means interconnecting said stations including a plurality of stationary elongated members having their lengths extending generally parallel to the line of said loading station, washing station and unloading station, spray means at said washing station located beneath said stationary dish-support means and perforated to direct spray upward onto objects supported by said stationary dish-support means, movable transport means having two disengageable portions each including a plurality of movable elongated members extending generally parallel to the line of said loading station, washing station and unloading station, and raisable from below said stationary dish-support means to a position interdigitated with said stationary elongated members to a position raised above said stationary elongated members for lifting dishes from said stationary elongated members, and further being movable lengthwise relative to said stationary elongated members to move dishes from one of said stations to an adjacent one of said stations, and means operable to move one of said disengageable portions out of engagement with the other of said disengageable portions and out of registry with said spray means.

2. A dishwashing machine comprising a loading station, a washing station and an unloading station arranged generally in a line, spray means at said washing station, stationary dishsupport means interconnecting said stations including a plurality of stationary elongated members having their lengths extending generally parallel to the line of said loading station, washing station and unloading station, movable transport means including a plurality of movable elongated members extending generally parallel to the line of said loading station, washing station and unloading station and raisable from below said stationary dish-support means through a position interdigitated with said stationary elongated members to a position raised above said stationary elongated members for lifting dishes from said stationary elongated members and further being movable lengthwise relative to said stationary elongated members to move dishes lengthwise thereof from one of said stations to an adjacent one of said stations, said washing station including a housing for spray means having opposite stationary sidewalls, a top portion bridging between said sidewalls and a movable end wall movable between a position closing an end of said housing and a position opening such housing end, and means for moving said movable endwall and said transport means in synchronism.

3. The dishwashing machine defined in claim 2, in which one of the disengageable portions is a loading rack portion and the other one of the disengageable portions is an unloading rack portion, and sequence control mechanism operable to effect sequentially engagement of said loading rack portion and said unloading rack portion, raising of said engaged rack portions in synchronism with movement of the movable endwall into end-opening position, transporting of said engaged rack portions lengthwise relative to the stationary dish-support means until said unloading rack portion is in registry with the unloading station and said loading rack portion is in registry with the washing station, lowering of said engaged rack portions in synchronism with movement of the movable endwall into end-closing position, disengagement of said engaged rack portions, movement of said loading rack portion out of registry with the washing station, supply of washing liquid through the spray means and simultaneous operation of said spray means effecting a predetermined washing cycle, and deenergization of the liquid supply and spray means at the end of such predetermined cycle.

4. The dishwashing machine defined in claim 2, and sequence control mechanism operable to effect sequentially movement of the movable endwall into end-opening position, reciprocation of the movable dish-support rack through the opening formed by opening the endwall into the washing station, movement of the movable endwall into end-closing position, supply of washing liquid to the spray means for a predetermined washing cycle, and termination of the liquid supply at the end of such predetermined washing cycle. 

